blend files open in 2.79 version instead of 2.83 when double clicked
Seems like you encounter the dumbest design the windows registry system can potentially have. If the executable name is the same one (.blend here), it will cause some bug and not updating the table correctly.
You can make your blender 2.79 executable named as blend279.exe. This will let the register miss the original 2.79 exe and update the new value after choosing new blend file.
example below to make it &quot;forget&quot; 2.83 blender: